import React, { Component } from 'react'

export default class App2 extends Component {
    UNSAFE_componentWillReceiveProps() {
        console.log('componentWillReceiveProps')
    }
    shouldComponentUpdate(nextProps) {
        return nextProps.num !== nextState.num
    }
    UNSAFE_componentWillMount(nextProps, nextState)
    render() {
        return (
            <div>App2</div>
        )
    }
}
class Sub extends Component {
    render() {
        return (
            <div>App3</div>
        )
    }
}
